The present invention relates to a novel method and composition used to chip seal a roadway.
Highways and roadways are usually paved with an asphalt matt. Such asphalt matt, may be a new base or a base several years old. To extend the life of such asphalt matts a "chip sealing" process has been extensively employed. This method normally entails placement of a relatively thin asphalt parent binding material atop the asphalt matt. Stone chips of high durability and high fracture plane characteristics are then spread atop the asphaltic parent binding material. These chips are also washed and screened to a certain size, which renders the chips as a very expensive component of the "chip seal" process. For example, the asphaltic parent binding material may be approximately 3/16 inch thick and the stone chips may be sized to approximately 3/8 of an inch. Ideally, half of each chip would extend above the parent binding material. Unfortunately, chips tend to stack one on top of another, pack too closely in a lateral direction, or do not adhere to the binding material for other reasons. Consequently, vehicular traffic tends to free stone chips from the parent material causing damage to vehicular windshields and bodies.
Prior art solutions to this problem have been to increase the amount of parent binding material, however this markedly reduces the skid resistance of the surface of the roadway and also increases the expense of the "chip seal" process. Excessive asphaltic binding material also tends to produce "bleeding" , a seepage of slippery asphaltic material which may produce a dangerous road condition. Repeated sweeping or brooming has also been employed after application of the stone chips. Unfortunately, even such extensive sweeping merely rolls loose chips from one of its flat surfaces to another flat surface. Experience has shown that loose chips still exist after such extensive brooming.
Preventing chip loss during the "chip seal" process on a roadway would be a great advance in the transportation field.